Problem: A new airplane SuperPuperJet has an infinite number of rows, numbered with positive integers starting with 1 from cockpit to tail. There are six seats in each row, denoted with letters from 'a' to 'f'. Seats 'a', 'b' and 'c' are located to the left of an aisle (if one looks in the direction of the cockpit), while seats 'd', 'e' and 'f' are located to the right. Seats 'a' and 'f' are located near the windows, while seats 'c' and 'd' are located near the aisle. 

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It's lunch time and two flight attendants have just started to serve food. They move from the first rows to the tail, always maintaining a distance of two rows from each other because of the food trolley. Thus, at the beginning the first attendant serves row 1 while the second attendant serves row 3. When both rows are done they move one row forward: the first attendant serves row 2 while the second attendant serves row 4. Then they move three rows forward and the first attendant serves row 5 while the second attendant serves row 7. Then they move one row forward again and so on.

Flight attendants work with the same speed: it takes exactly 1 second to serve one passenger and 1 second to move one row forward. Each attendant first serves the passengers on the seats to the right of the aisle and then serves passengers on the seats to the left of the aisle (if one looks in the direction of the cockpit). Moreover, they always serve passengers in order from the window to the aisle. Thus, the first passenger to receive food in each row is located in seat 'f', and the last one — in seat 'c'. Assume that all seats are occupied.

Vasya has seat s in row n and wants to know how many seconds will pass before he gets his lunch.

Input

The only line of input contains a description of Vasya's seat in the format ns, where n (1 ≤ n ≤ 1018) is the index of the row and s is the seat in this row, denoted as letter from 'a' to 'f'. The index of the row and the seat are not separated by a space.

Output

Print one integer — the number of seconds Vasya has to wait until he gets his lunch.

Examples

Input

1f


Output

1


Input

2d


Output

10


Input

4a


Output

11


Input

5e


Output

18

Note

In the first sample, the first flight attendant serves Vasya first, so Vasya gets his lunch after 1 second.

In the second sample, the flight attendants will spend 6 seconds to serve everyone in the rows 1 and 3, then they will move one row forward in 1 second. As they first serve seats located to the right of the aisle in order from window to aisle, Vasya has to wait 3 more seconds. The total is 6 + 1 + 3 = 10.

Solution (in JAVA):

Solution:
import java.io.*;
import java.util.*;


public class Solution {
    private BufferedReader in;
    private StringTokenizer line;
    private PrintWriter out;
    private boolean isDebug;

    public Solution(boolean isDebug) {
        this.isDebug = isDebug;
    }

    private static final long mm = 1000000007;

    private long mult(long a, long b) {
        return a * b % mm;
    }

    private long pow(long a, long n) {
        if (n == 0) {
            return 1;
        }
        long t = pow(a, n / 2);
        t = mult(t, t);
        if (n % 2 != 0) {
            t = mult(t, a);
        }
        return t;
    }

    private void solve() throws IOException {
        String s = nextToken();
        char ch = s.charAt(s.length() - 1);
        s = s.substring(0, s.length() - 1);
        long num = new Long(s) - 1;
        long res = num / 4 * 16;
        num %= 4;
        if (num % 2 != 0) {
            res += 7;
        }
        switch (ch) {
            case 'f':
                res += 1;
                break;
            case 'e':
                res += 2;
                break;
            case 'd':
                res += 3;
                break;
            case 'a':
                res += 4;
                break;
            case 'b':
                res += 5;
                break;
            case 'c':
                res += 6;
                break;
        }
        out.println(res);
    }

    public static void main(String[] args) throws IOException {
        new Solution(args.length > 0 && "DEBUG_MODE".equals(args[0])).run(args);
    }

    public void run(String[] args) throws IOException {
        if (isDebug) {
            in = new BufferedReader(new InputStreamReader(new FileInputStream("input.txt")));
        } else {
            in = new BufferedReader(new InputStreamReader(System.in));
        }
        out = new PrintWriter(System.out);
//        out = new PrintWriter("output.txt");

//        long start_time = System.nanoTime();

//        int t = nextInt();
        int t = 1;
//        int t = isDebug ? nextInt() : 1;
        for (int i = 0; i < t; i++) {
//            out.print("Case #" + (i + 1) + ": ");
            solve();
        }
//
//        long end_time = System.nanoTime();
//        if (isDebug) {
//            out.println(String.format("<<<<< %.6f >>>>>", (end_time - start_time) / 1e9));
//        }

        in.close();
        out.flush();
        out.close();
    }

    private int[] nextIntArray(int n) throws IOException {
        int[] res = new int[n];
        for (int i = 0; i < n; i++) {
            res[i] = nextInt();
        }
        return res;
    }

    private long[] nextLongArray(int n) throws IOException {
        long[] res = new long[n];
        for (int i = 0; i < n; i++) {
            res[i] = nextLong();
        }
        return res;
    }

    private int nextInt() throws IOException {
        return Integer.parseInt(nextToken());
    }

    private long nextLong() throws IOException {
        return Long.parseLong(nextToken());
    }

    private double nextDouble() throws IOException {
        return Double.parseDouble(nextToken());
    }

    private String nextToken() throws IOException {
        while (line == null || !line.hasMoreTokens()) {
            line = new StringTokenizer(in.readLine());
        }
        return line.nextToken();
    }

    private static class Pll {
        private long key;
        private long value;

        public Pll(long key, long value) {
            this.key = key;
            this.value = value;
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;

            Pll pll = (Pll) o;

            if (key != pll.key) return false;
            return value == pll.value;

        }

        @Override
        public int hashCode() {
            int result = (int) (key ^ (key >>> 32));
            result = 31 * result + (int) (value ^ (value >>> 32));
            return result;
        }
    }

    private static class Pii {
        private int key;
        private int value;

        public Pii(int key, int value) {
            this.key = key;
            this.value = value;
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;

            Pii pii = (Pii) o;

            if (key != pii.key) return false;
            return value == pii.value;

        }

        @Override
        public int hashCode() {
            int result = key;
            result = 31 * result + value;
            return result;
        }

        @Override
        public String toString() {
            return "Pii{" +
                    "key=" + key +
                    ", value=" + value +
                    '}';
        }
    }

    private static class Pair<K, V> {
        private K key;
        private V value;

        public Pair(K key, V value) {
            this.key = key;
            this.value = value;
        }

        public K getKey() {
            return key;
        }

        public V getValue() {
            return value;
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;

            Pair<?, ?> pair = (Pair<?, ?>) o;

            if (key != null ? !key.equals(pair.key) : pair.key != null) return false;
            return !(value != null ? !value.equals(pair.value) : pair.value != null);

        }

        @Override
        public int hashCode() {
            int result = key != null ? key.hashCode() : 0;
            result = 31 * result + (value != null ? value.hashCode() : 0);
            return result;
        }

        @Override
        public String toString() {
            return "Pair{" +
                    "key=" + key +
                    ", value=" + value +
                    '}';
        }
    }
}